Working out with just dumbbells

[Fishmonger]

I´ve been doing some light workouts recently, aiming to feel fitter and stronger. Mostly 1-2 mile runs, push-ups and sit-ups. I feel like it´s working but I want to do some more serious weight training. Unfortunately there are no decent gyms near where I live. So I ask what are the best exercises that can be done with dumbbells alone, and could someone sketch out a decent lifting routine using these exercises? I´m 5´8, 160 and quite skinny in the chest and arms.